LXR linux/include/linux/hdlc.h

   1/*
   2 * Generic HDLC support routines for Linux
   3 *
   4 * Copyright (C) 1999-2005 Krzysztof Halasa <khc@pm.waw.pl>
   5 *
   6 * This program is free software; you can redistribute it and/or modify it
   7 * under the terms of version 2 of the GNU General Public License
   8 * as published by the Free Software Foundation.
   9 */
  10
  11#ifndef __HDLC_H
  12#define __HDLC_H
  13
  14
  15#define HDLC_MAX_MTU 1500       /* Ethernet 1500 bytes */
  16#if 0
  17#define HDLC_MAX_MRU (HDLC_MAX_MTU + 10 + 14 + 4) /* for ETH+VLAN over FR */
  18#else
  19#define HDLC_MAX_MRU 1600 /* as required for FR network */
  20#endif
  21
  22
  23#ifdef __KERNEL__
  24
  25#include <linux/skbuff.h>
  26#include <linux/netdevice.h>
  27#include <linux/hdlc/ioctl.h>
  28
  29
  30/* Used by all network devices here, pointed to by netdev_priv(dev) */
  31struct hdlc_device_desc {
  32        int (*netif_rx)(struct sk_buff *skb);
  33        struct net_device_stats stats;
  34};
  35
  36/* This structure is a private property of HDLC protocols.
  37   Hardware drivers have no interest here */
  38
  39struct hdlc_proto {
  40        int (*open)(struct net_device *dev);
  41        void (*close)(struct net_device *dev);
  42        void (*start)(struct net_device *dev); /* if open & DCD */
  43        void (*stop)(struct net_device *dev); /* if open & !DCD */
  44        void (*detach)(struct net_device *dev);
  45        int (*ioctl)(struct net_device *dev, struct ifreq *ifr);
  46        __be16 (*type_trans)(struct sk_buff *skb, struct net_device *dev);
  47        struct module *module;
  48        struct hdlc_proto *next; /* next protocol in the list */
  49};
  50
  51
  52typedef struct hdlc_device {
  53        /* used by HDLC layer to take control over HDLC device from hw driver*/
  54        int (*attach)(struct net_device *dev,
  55                      unsigned short encoding, unsigned short parity);
  56
  57        /* hardware driver must handle this instead of dev->hard_start_xmit */
  58        int (*xmit)(struct sk_buff *skb, struct net_device *dev);
  59
  60        /* Things below are for HDLC layer internal use only */
  61        const struct hdlc_proto *proto;
  62        int carrier;
  63        int open;
  64        spinlock_t state_lock;
  65        void *state;
  66        void *priv;
  67}hdlc_device;
  68
  69
  70
  71/* Exported from hdlc module */
  72
  73/* Called by hardware driver when a user requests HDLC service */
  74int hdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd);
  75
  76/* Must be used by hardware driver on module startup/exit */
  77#define register_hdlc_device(dev)       register_netdev(dev)
  78void unregister_hdlc_device(struct net_device *dev);
  79
  80
  81void register_hdlc_protocol(struct hdlc_proto *proto);
  82void unregister_hdlc_protocol(struct hdlc_proto *proto);
  83
  84struct net_device *alloc_hdlcdev(void *priv);
  85
  86
  87static __inline__ struct hdlc_device_desc* dev_to_desc(struct net_device *dev)
  88{
  89        return netdev_priv(dev);
  90}
  91
  92static __inline__ hdlc_device* dev_to_hdlc(struct net_device *dev)
  93{
  94        return netdev_priv(dev) + sizeof(struct hdlc_device_desc);
  95}
  96
  97
  98static __inline__ void debug_frame(const struct sk_buff *skb)
  99{
 100        int i;
 101
 102        for (i=0; i < skb->len; i++) {
 103                if (i == 100) {
 104                        printk("...\n");
 105                        return;
 106                }
 107                printk(" %02X", skb->data[i]);
 108        }
 109        printk("\n");
 110}
 111
 112
 113/* Must be called by hardware driver when HDLC device is being opened */
 114int hdlc_open(struct net_device *dev);
 115/* Must be called by hardware driver when HDLC device is being closed */
 116void hdlc_close(struct net_device *dev);
 117
 118int attach_hdlc_protocol(struct net_device *dev, struct hdlc_proto *proto,
 119                         int (*rx)(struct sk_buff *skb), size_t size);
 120/* May be used by hardware driver to gain control over HDLC device */
 121void detach_hdlc_protocol(struct net_device *dev);
 122
 123static __inline__ struct net_device_stats *hdlc_stats(struct net_device *dev)
 124{
 125        return &dev_to_desc(dev)->stats;
 126}
 127
 128
 129static __inline__ __be16 hdlc_type_trans(struct sk_buff *skb,
 130                                         struct net_device *dev)
 131{
 132        hdlc_device *hdlc = dev_to_hdlc(dev);
 133
 134        skb->dev = dev;
 135        skb_reset_mac_header(skb);
 136
 137        if (hdlc->proto->type_trans)
 138                return hdlc->proto->type_trans(skb, dev);
 139        else
 140                return htons(ETH_P_HDLC);
 141}
 142
 143#endif /* __KERNEL */
 144#endif /* __HDLC_H */
 145